Kecoeding means



AVAILABIE c6 1 R J, wlsE l' nEcoR MEANS Fil May 251935 Aug. 25, 194

Patented Aug. 25, 1942 STATES I RECORDING MEAN S Raleigh 3. Wise, Dunellen, N.'J., Bernard L. Kline,

- Manhasset, N. Y., and Maurice A. Rudd; North Plainfield, N. 3., assignors to The Western Union Telegraph Company, New York, N. Y., a corporation of New York Application Mar 28, 1935, Serial No. 23sec 15 Claims. (01. 204-2) The present invention relates to a method of the passage of current therethrough. Mercuric and means for recording in which a mark or oxide in yellow form may be changed to the red series of marks is made upon a recording medium. form upon passage of current therethrough.

Its principal object is toprovide an economical The current requiredto effect the change in ala and improved recording medium and amethod of 'lotropic form is relatively small and hencethis marking useful for recorders of various kinds, recording medium provides a sensitive means for particularly where occurrences of short time producing permanent records of electrical varduration must be accurately recorded at high iationsg It is particularlyadaptable to facsimspeeds, as for example in telegraph and facsimile ile ecordin although s use is not limited recording. thereto as will be apparent from the following The present available recording systems gendetailed description of the invention taken in erally produce marks upon the recording medium conjunction with the accompanying drawing in by applying a marking material such as carbon which:

or ink; by removing a masking material and ex- Fig. 1 is a perspective view of the recording posing a surface of contrasting appearance; or 10 medium and a simplified marking means illusby effecting a chemical change of the recording trating thc prin iple f the i v n n medium. In some of these processes the change Fig. 2 is a perspec ive View Of t e co d is not immediately evident, but can be made to m d um and a markin m ans illustr in th show the mark by a developing-process. The application of the invention to thewell known known marking systems are generally objection- 2U mechanisms for obtaining continuous records of able in necessitating the maintenance of the industrial operat o s, and

marking ink or equivalent; in requiring careful Fi 3 is a diagrammatic view of a facsimile handling of the recording medium to avoid 8,2611 transmitting and recording means utilizing t e dental marks; in requiring a moist medium; in present ve n. producing a non-permanent record, or in being Referring t0 there is Shown 8; recording limited in the speed at which marks can be made. medium which may consist of a b e o sun- The present-invention provides a cheap mark- P Of Conducting P p metal 0 01' milar ing medium or paper which can b prepared i conducting material coated or impregnated with advance, stored and handled like ordinary paper a a lotr pi fo m f a m ur su phid Th with deterioration or change, and which is base lmay con o a porous p pe i p a adapted to be permanently marked by simple with a conducting substance such as an inormeans.

The present invention is based upon the disin Solution c a Conducting 0 semi-concovery that when certain substances are sub ducting p is u y s sed n a imp ndi jected to a difference in electrical potential, their app of i Se al o. 3 55, filed form may be changed from one stable allotropic July 1935,, W Patent i ed form to another, the change in form occurring January 21, 1941- Bri fiy, the paper is rendered practically instantly and only at the point or ,conducting y impregnating it w po ass points of application of the electrical potential. iodide, Sodium b m de 01' a S milar Saltv dis- The change produced i t bl i t t solved in a suitable solvent such as triethylene ganic salt which has a high dissociation constant I being affected by ordinary atmospheric condiglycol. Of course other forms of conducting pations, by light or by handling. Examples of such per may be used. The allotropic compounds, as substances are mercuric compounds such as merfor instance, the ermilion form of mercuric curic sulphide, mercuric iodide, and mercuric sulphide may b added t th paper l ith Oxid- For instance, h {mercuric sulphide in a suitable sizing material, such as rosin and Vermilion form is applied in a thin coating to made in integral part of the Sheet, it may be a base Such as paper or meta1.and current is applied to the manufactured sheet by impregnapassed therethmugh the coatmg changes from tion or as a coating. For instance, the powdered g g gz g fi g g i iii iz gg fiiz ggf cinnabar or Vermilion form of mercuric sulphide may be ground in oil and applied as an ink or ble unedr ordinary conditions of storing and d d b t t handling and the contrast between the two forms plgment' or It may be suspen e m car on e is sharp. Similarly mercuric iodide in red form chloride and suitable binder, such as ubber may be changed to a yellow form, due t th cement, or it may be suspended in alcohol conmolecular rearrangement of its structure upon taining a soluble binder such as shellac and changes on power supply lines.

applied to the sheet by spraying, or in any other suitable manner.

While the recording medium is shown as a flat sheet in Fig. 1, it preferably should be 01 a flexible nature so that it may be rolled, as shown in Fig. 2. or applied to the surface of a cylinder, as shown in Fig. 3. While conducting paper is preferred, it is not essential, however, since with increased potentials, a non-conducting paper may be employed. The platen 2 of metallof other conducting material serves as a support for the recording medium. The pencil or stylus 8 is assumed to be movable so that it may be placed upon the recording medium or paper at any point at which it is desired to mark the paper; The platen 2 and stylus 3 are connected to a source of electric current 4 so that a current flows through the mercuric sulphide when the stylus is touched to the paper. At any such point, the mercuric sulphide will undergo an allotropic change from Vermilion to black and thus any desired legend may be written upon the recording medium by suitably moving the stylus thereover. The allotropic change may be accompanied by some chemical changes of a portion of the mercuric sulphide which donot, however, prevent the alteration of color due to the change in the allotropic form of the recording medium.

Fig, 2 illustrates a type of recorder commonly used to obtain continuous records of voltage The recording medium of the present invention has been substituted for the 'usual ink marking device employed on such devices. 5 consists of a thin metal foil which has been coated with vermilion mercuric sulphide. The

chart ruling and designations which may be desirable for the particular recorder may be provided by printing them in the desired color upon the Vermilion, by printing the foil with the vermilion at all points except where desired for chart designations. or any other means evident to those skilled in the art.

In the form shown, the recording medium is drawn over the platen 6 and under the stylus l which is maintained in contact with the mercuric sulphide coating. The stylus l is attached to the needle extension of a voltmeter mechanism 8. The voltmeter when connected across the observed current supply line it causes the stylus l to assume different vertical positions corresponding to the voltage of the supply line. The platen G and the stylus l are connected to an electric power supply by conductors iii and H, which power supply in the particular embodiment shown, is the same as that being observed. The current in passing through the mercuric sulphide will change its color from Vermilion to black, thus tracing a record of the movements of the stylus.

In Fig. 3 are shown two drums l2 and It which are assumed to be synchronously driven by the motors l5 and I6. Drum I2 is the sending instrument of a facsimile system in which the message or picture to be transmitted is scanned and the successive signals over a line depend upon the nature of the picture or message being scanned. Such a system is described in a copending application of R. J. Wise, Serial No. 23,928, filed May 28, 1935, and entitled Telegraphic transmission of intelligence, now Patent No. 2,153,858, issued April 11, 1939.

The recording medium I? consists of a paper or similar support to which has been applied a The recording medium coating of Vermilion mercuric sulphide. The stylus I8 is adapted to move longitudinally as drum l3 rotates so that the stylus traces a helical path on the recording medium.

For purposes of illustration a simple electric circuit is shown comprising a source of current It, conductor 20, drum l2, the transmitting copy 2|, the sending stylus 22, conductor 23, the receiving stylus It, the recording medium i1, drum l3 and conductor 24. As explained in the aforesaid copending application, a current will flow through this electric circuit when the sending stylus 22 contacts a printed portion of the transmitting copy 2l. This current passing through the mercuric sulphide of the recording medium'll produces a black mark. Thus, marks are made on the recording medium corresponding to those on the transmitting copy and the transmitting copy is reproduced on the recording medium.

It will be understood that in practice, the

simple circuit illustrated may for better elliciency be replaced by various arrangements for transmitting electrical impulses which are well known in the communication art.

What is claimedis: 1. The method of recording which comprises passing an electric current through selected elemental areas of a surface portion of an allotropic form of a mercuric compound in such manner as to cause said compound [to change to another allotropic form and alter its color in those elemental areas through which the current is passed.

2. A method of recording which comprises applying to a base a coating of an electrically sensitive allotropic form of a mercuric compound having two allotropic forms of different color, and selectively passing electric current through selected elemental areas of said coating to effect a change in the allotropic form of the coating and alter its color in those elemental areas through which the current is passed.

3. The method of marking which comprises applying an electrical potential to a record sheet comprising an electrically conductive backing coated with Vermilion mercuric sulphide and thereby changing the color or the surface of the record sheet from Vermilion to black.

4, A recording medium comprising a base carrying an electric current sensitive allotropic form of a mercuric compound which alters its color when an electric current is passed through the compound.

5. A recording medium comprising an electrically conductive support carrying an electric current sensitive allotropic form of a mercuric compound which alters its color when an electric current is passed through the compound.

6. A recording medium comprising a metallic base carrying an electric current sensitive allotroplc form of a mercuric compound which alters its color when an electric current is passed through the compound.

7. A recording medium comprising a base carrying an electric current sensitive allotropic form of a mercuric compound which alters its color when an electric current is passed through the compound, said compound comprising one or,

compound comprising one or more oi the group consisting oi mercuric sulphide. mercuric iodide and mercuric oxide.

; tive support, a coating of a lacquer on said sup- 7 9. An electrosensitive recording medium comprising a support having a coating of Vermilion mercuric sulphide "applied therto.

10. An electrosensitive recording medium comprising a support and a coating of vermilion electrically conducting paper and a coating thereon oi Vermilion mercuric sulphide.

14. A recording medium comprising a conducport, said lacquer containing an electric current sensitive allotropic form or a mercuric compound which compound is convertible to another allotropic form of a diflerent color upon passing electric current therethrough.

15. A recording medium comprising a conductive support, a coating of a lacquer on said support, said lacquer being composed of shellac in alcohol and containing vermilion mercuric suiphide which is subject to color change upon passage of an electric current theretl rough.

RALEIGH J. was. BERNARD n. MAURICE a. RUDD. 

